Impact tool



July 7, s. SANTI mmcm TOOL Filed Dec. 18, 1968 FIG].

FIG. 2..

INVENTOR United States Patent 3,519,087 IMPACT TOOL Silvio Santi, 262Margueretta St., Toronto, Ontario, Canada Filed Dec. 18, 1968, Ser. No.784,607 Int. Cl. B25d 17/00 US. Cl. 173-91 4 Claims ABSTRACT OF THEDISCLOSURE An impact tool comprised of a tubular handle having a toolbit secured thereto and a striker slidably movable within the handle toimpinge either one of two stops at each end of the handle. The strikeris connected by an elongated shaft to a heavy grip for applying highmomentum impact strokes to either stop and hence to the tool bit.

This invention relates to an impact tool of the type wherein impetus isdelivered to a tool head thereof by percussive engagement of a weightedmovable part of the tool directly or indirectly with the tool head.

Known impact tools have included an elongated shaft having a handle atone end and a tool head at the other, both handle and head beingprovided with stops permitting impetus to the imparted to the tool headin each of two opposite directions by a weighted sleeve slidably movableon the shaft for impinging upon said stops. The weighted sleeve of sucha tool is manually gripped and moved along the shaft by one hand of theoperator whilst the operators other hand holds the tool handle.

It is a broad object of the present invention to provide an impact toolof simple, yet sturdy, construction which is reliable in use and whichis easily useablein situations of difficult acceess. For example, theinstant impact tool may be particularly advantageously utilized in theremoval of dents from automobile body panels wherein it is frequentlynecessary to engage a tool head thereof with the body panel in are-entrant section thereof.

It is a further object of the invention to provide such an impact toolcapable of delivering impact strokes to its tool head in either a pushor pull direction and it is another object of the invention to providesuch a tool wherein the tool head and/ or a tool bit thereof is readilyremovable and replaceable with another type of head or bit.

It is a yet further object to provide such an impact tool having aWeighted grip for applying a relatively large momentum to a strikerwhich, in turn, appiles impetus to the tool head upon direct or indirectimpact therewith and it is an associated object to provide such animpact tool wherein the weight of the grip is adjustable.

In accordance with the invention, there'is provided an impact toolhaving ahandle and tool head connected thereto, a shaft movable relativeto the handle having a striker at one end an da grip at the other, theshaft, grip and striker being co-movable towards and away from the toolhead for delivering an impact stroke thereto in each of two directions.The said handle is preferably of tubular form with a stop providedadjacent each end thereof, said striker being captive and movablebetween said st ps for selective impingement therewith for deliveringimpetus to said tool head in a desired push or pull direction.

Other objects of the invention, more or less broad than the foregoing,will become apparent from the hereinafter following description of theparts, principles and elements of the invention given herein solely byway of example with reference to the accompanying drawings wherein:

FIG. 1 is a side cross-sectional view of the instant tool and ice

FIG. 2 is a partly sectional exploded perspective view of the tool.

As illustrated herein, the impact tool of the invention is comprisedessentially of a handle assembly H providing a bearing for a strikerassembly S. The handle assembly H includes a tool head 10 engaged with ahandle 12 whilst the striker assembly S includes an elongated shaft 14having a grip 16 and a striker 18 connected to opposite ends of saidshaft 14; the shaft 14, grip 16 and striker 18 all being co-movabletogether.

In accordance with the inventive concept, the striker assembly S ismovable in two opposite directions respectively relative to the handleassembly H towards and away from the tool head 10 for delivering animpact stroke in each of said directions, each said impact strokeimparting an impetus to the tool head 10. Such an arrangement of partsenables the impetus to be imparted to the tool head 10 in eitherdirection corresponding to the direction of movement of the strikerassembly S. Thus, referring to the drawings, when the striker assembly Sis moved downwardly, impetus will be imparted to the tool head 10 in adownward direction thereby giving rise to a push stroke to the tool head10 whilst, conversely, upward movement of the striker assembly S willgive an impetus to the tool head 10 in an upward direction resulting ina pull stroke of the tool head 10.

Referring now to the drawing in more detail, it will be seen that, inthe present embodiment, the handle 12 itself is comprised of anelongated tubular member providing accommodation for an elongated shaft14 of circular cross-section reciprocably slidable Within the handle 12.That end 14a of the shaft 14 which is located within the handle 12carries the striker 18 thereon whilst the other end 14b of the shaft 14carries the grip 16; the striker 18 having a circular transversecross-section of external diameter slightly less than the internaldiameter of the handle 12 thereby permitting a sliding fit of thestriker 18 within the handle 12 and hence providing a bearing within thehandle 12 for the shaft 14. That end of the handle 12 adjacent the grip16 is provided with a bushing 20 providing further bearing for the shaft14 and having an internal diameter of somewhat less than the externaldiameter of the striker 18 so that it is captively retained within thehandle 12 against movement thereof in an upward direction as shown inthe drawings.

The other end of the handle 12 carries the tool head 10 detachablysecured thereon by a suitable connection such as the screw-threadedconnection illustrated in the drawings. All of the parts of the impacttool may be in detachable engagement one with another such as byscrewthreaded connection; thus, as illustrated herein, the striker 18 isscrew-threadedly engaged upon the shaft 14 at one end thereof whilst thegrip 16 is screw-threadedly engageable thereon at the other end and thebushing 20 is screwthreadedly engaged upon that end of the handle 12remote from the tool head 10. The grip 16 itself is of a substantialweight so as to be capable of imparting a relatively large momentum tothe striker assembly S upon movement thereof relative to the tool head10 for applying a relatively high impetus to the tool head 10 asdesired. The aforesaid weighted grip 16 is comprised of a plurality ofweights 16a, 16b, all detachably secured one to another such as by thescrew-threaded connections illustrated whereby the effective momentum ofthe striker assembly S may be adjusted as desired.

As mentioned hereinbefore, the bushing 20 has an internal diameter sodimensioned as to retain the striker 18 within the handle 12 uponmovement of the striker 18 towards the bushing 20. As will be seen fromthe draw ings, the bushing 20 is comprised of a relatively largediameter body 22 screw-threadedly engaged upon the exterior of thehandle and an annular centrally-apertured flange 24 forming a part ofthe bearing for the shaft 14. By virtue of the reduced internal diameterof flange 24, there is provided a stop (referred to herein by the samenumeral 24) for arresting movement of the striker assembly S uponmovement thereof in a direction away from the tool head 10. Thus, whensuch movement is arrested by impingement of the striker 18 upon thebushing flange 24, an impetus is imparted to the tool head resulting ina pull stroke thereto.

In the present embodiment, impetus is imparted to the tool head 10 inthe opposite direction, i.e. downwardly as shown in the drawings,resulting in a push stroke to the tool head 10 by the provision of asecond stop 26 for arresting movement of the striker 18 in this saiddirection. Such stop 26 is engaged with handle 12 in spaced and relationwith the stop 24 provided by the aforesaid bushing flange therebyretaining the striker 18 captive within the handle 12 between the twostops 24-26 and, in the present embodiment, said second stop 26 is, infact, provided on the detachable tool head 10 itself. Therefore,downward movement of the striker assembly S will cause the striker 18 toimpinge said second stop 26 (at the position shown in dotted line inFIG. 1) with consequent arrest of movement of the assembly S and theimparting of an impetus to the tool head 10 in the same direction, i.e.downwardly as shown in the drawings.

It will be appreciated that, since the tool head 10 is detachable by thesimple expedient of unscrewing it relative to the handle, any desiredshape or form of tool head 10 may be fitted upon the tool adapted foreither a push or pull strike or both dependent upon the type of workrequired to be carried out by the tool. The tool head 10 may carry atool bit proper integral therewith or, as illustrated herein, it may beprovided with a connector such as threaded stud 10a, for detachablymounting a tool bit thereon, in which case interchange of tool bits maybe accomplished as desired without detaching the tool head 10 from thehandle 12. For example, as shown in FIG. 1, a chuck 28 may be mountedupon tool head 10 for carrying a tool bit thereon. Also, since the shaft14 is itself readily detachable from the grip 16 and striker 18, a shaft14 of any desired length may be installed in the tool with a striker 18at one end captive within the handle 12 between the two stops 2426 and aweighted grip 16 at the other end whereby the tool may be used inlocations which are of difficult access. In particular, it is envisagedthat the instant tool be used for the knocking out of dents inautomobile body panels, which work is normally required to be carriedout on the inner surface of such panels and which often includesreentrant angles normally diflicult of access.

It will be appreciated that the instant tool may be grasped by, forexample, the left hand of the operator holding the handle 12 with thetool head in engagement with the part of the work to be hammered, whilstthe right hand of the operator grasps the grip 16. Thus if an extremelylong shaft 14 is utilized, the grip 16 may be some considerable distancefrom the tool head 10 and handle 12 whereby the operator may freely movehis rigrt hand to impart hammering strokes in either a push or pulldirection to the tool head 10 thereby imparting the required hammerblows to the work.

It will be appreciated that the hereinbefore described 4 embodiments ofthe invention have been selected solely for the expository purposeshereof and should not be construed in a limiting sense; variousmodifications being readily suggestible to those skilled in the art andthe true scope of the invention being restricted only by the claimshereinafter set forth. What I claim is: 1. A heavy duty impact toolincluding: an elongated tubular handle; a tool head at one end of saidhandle; a stop adjacent said tool head occluding the interior of saidhandle and, a bushing detachably secured to the other end of saidhandle; an elongated shaft; a striker detachably secured to one end ofsaid shaft,

and a weighted grip detachably secured to the other end of said shaft;said striker being captive within said handle and co-movable, togetherwith said shaft and said weighted grip, towards said stop for procuringimpingement thereon by said striker for imparting impetus to said toolhead in one direction, the interior of said handle providing a bearingfor said striker and the bushing providing a bearing for said shaft,said bushing being removable from said handle and said striker beingremovable from said shaft permitting removal of said shaft through thatend of the handle remote from the tool head and said grip also beingremovable from said shaft to permit interchangeability of said shaftwith another shaft of different length assemblable with said grip,striker, bushing and handle. 2. An impact tool as claimed in claim 1wherein: said bushing constitutes a stop impingeable by said strikerwhen it is moved away from said tool head for imparting impetus to saidtool head in the opposite direction to said aforesaid. 3. An impact toolas claimed in claim 1 wherein: said tool head and said stop aredetachably secured to said handle and removable therefrom, together withsaid bushing, permitting interchangeability of said handle with anotherhandle of different length assemblable with said tool head, stop andbushing. 4. An impact tool as claimed oin claim 3 wherein: said stop andsaid tool head are integral with one another.

References Cited UNITED STATES PATENTS 5/1866 Burnham 30--164.6 7/1883Armstrong 30277 X 8/1893 Teufel 30-277 X 6/1964 Bauer et a1. 17391 X4/1966 Williams et al. 173126

